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Date: | Wed, 30 Oct 1996 13:56:00 -0500 |
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A review of J-STD-001A, par 7.1.7, and J-STD-001B(draft), par 7.1.5
indicate a change from the requirements of the cancelled Military
specifications..ie... MIL-STD-2000, par 5.6.5.4, and 2000A, par
5.1.8. The requirement to reflow a PWA that has had leads cut after
soldering appears to be eased. The cancelled specifications did not
provide any latitude, but required all cut connections to be reflowed.
The J-STDs allow the solder joints to either be reflowed or to be
inspected for surface fractures at 10X. My understanding of the
process is that reflow of a PWA is required when lead cutting is
performed after soldering in order to eliminate any micro-fractures that
may have occured due to the side loading effect of the lead trimming
process. The micro-fractures that occur may not only be surface
fractures but could be internal and therfore not detectable by surface
10X inspection.
I would appreciate if you could provide me with any information
regarding surface vs internal micro-fractures occuring during the
trimming process.
Angelo Scarcella
DCMDE-OTDP
495 Summer St.
Boston, MA 02210
tel. (617) 753-4892, FAX (617) 753-4250
e-mail: [log in to unmask]
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